<!DOCTYPE html>
<title>CSS Anchor Positioning: basic position-area positioning</title>
<link rel="help" href="https://drafts.csswg.org/css-anchor-position/#position-area">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<!-- The grid:

          100      150      150
      +--------+--------+--------+
      |        |        |        |
  150 |        |        |        |
      |        |        |        |
      +--------+--------+--------+
      |        |        |        |
   75 |        |        |        |
      |        |        |        |
      +--------+--------+--------+
      |        |        |        |
  175 |        |        |        |
      |        |        |        |
      +--------+--------+--------+

  -->
<style>
  #container {
    position: absolute;
    width: 400px;
    height: 400px;
  }
  #anchored {
    position: absolute;
    align-self: stretch;
    justify-self: stretch;
    position-anchor: --anchor;
  }
  #anchor {
    margin-top: 150px;
    margin-left: 100px;
    width: 150px;
    height: 75px;
    anchor-name: --anchor;
  }
</style>
<div id="container">
  <div id="anchored"></div>
  <div id="anchor"></div>
</div>
<script>
  function test_position_area(position_area, expected_offsets) {
    anchored.style.positionArea = position_area;
    test(() => {
      assert_equals(anchored.offsetLeft, expected_offsets.left, "Check expected offsetLeft");
      assert_equals(anchored.offsetTop, expected_offsets.top, "Check expected offsetTop");
      assert_equals(anchored.offsetWidth, expected_offsets.width, "Check expected offsetWidth");
      assert_equals(anchored.offsetHeight, expected_offsets.height, "Check expected offsetHeight");
    }, "Offsets for: " + position_area);
  }

  test_position_area("none", {left:0, top:0, width:0, height:0});
  test_position_area("span-all", {left:0, top:0, width:400, height:400});
  test_position_area("span-all span-all", {left:0, top:0, width:400, height:400});

  // Single region spans
  test_position_area("top left", {left:0, top:0, width:100, height:150});
  test_position_area("top center", {left:100, top:0, width:150, height:150});
  test_position_area("top right", {left:250, top:0, width:150, height:150});
  test_position_area("center left", {left:0, top:150, width:100, height:75});
  test_position_area("center center", {left:100, top:150, width:150, height:75});
  test_position_area("center right", {left:250, top:150, width:150, height:75});
  test_position_area("bottom left", {left:0, top:225, width:100, height:175});
  test_position_area("bottom center", {left:100, top:225, width:150, height:175});
  test_position_area("bottom right", {left:250, top:225, width:150, height:175});

  test_position_area("start start", {left:0, top:0, width:100, height:150});
  test_position_area("start center", {left:100, top:0, width:150, height:150});
  test_position_area("start end", {left:250, top:0, width:150, height:150});
  test_position_area("center start", {left:0, top:150, width:100, height:75});
  test_position_area("center end", {left:250, top:150, width:150, height:75});
  test_position_area("end start", {left:0, top:225, width:100, height:175});
  test_position_area("end center", {left:100, top:225, width:150, height:175});
  test_position_area("end end", {left:250, top:225, width:150, height:175});

  test_position_area("self-start self-start", {left:0, top:0, width:100, height:150});
  test_position_area("self-start center", {left:100, top:0, width:150, height:150});
  test_position_area("self-start self-end", {left:250, top:0, width:150, height:150});
  test_position_area("center self-start", {left:0, top:150, width:100, height:75});
  test_position_area("center self-end", {left:250, top:150, width:150, height:75});
  test_position_area("self-end self-start", {left:0, top:225, width:100, height:175});
  test_position_area("self-end center", {left:100, top:225, width:150, height:175});
  test_position_area("self-end self-end", {left:250, top:225, width:150, height:175});

  test_position_area("y-start x-start", {left:0, top:0, width:100, height:150});
  test_position_area("y-start center", {left:100, top:0, width:150, height:150});
  test_position_area("y-start x-end", {left:250, top:0, width:150, height:150});
  test_position_area("center x-start", {left:0, top:150, width:100, height:75});
  test_position_area("center x-end", {left:250, top:150, width:150, height:75});
  test_position_area("y-end x-start", {left:0, top:225, width:100, height:175});
  test_position_area("y-end center", {left:100, top:225, width:150, height:175});
  test_position_area("y-end x-end", {left:250, top:225, width:150, height:175});

  test_position_area("y-self-start x-self-start", {left:0, top:0, width:100, height:150});
  test_position_area("y-self-start center", {left:100, top:0, width:150, height:150});
  test_position_area("y-self-start x-self-end", {left:250, top:0, width:150, height:150});
  test_position_area("center x-self-start", {left:0, top:150, width:100, height:75});
  test_position_area("center x-self-end", {left:250, top:150, width:150, height:75});
  test_position_area("y-self-end x-self-start", {left:0, top:225, width:100, height:175});
  test_position_area("y-self-end center", {left:100, top:225, width:150, height:175});
  test_position_area("y-self-end x-self-end", {left:250, top:225, width:150, height:175});

  // Multi-region spans
  test_position_area("span-y-self-start span-x-self-end", {left:100, top:0, width:300, height:225});
  test_position_area("span-bottom span-all", {left:0, top:150, width:400, height:250});

  // No implicit anchor means the position-area should not apply.
  anchored.style.positionAnchor = "auto";
  test_position_area("span-all top", {left:0, top:0, width:0, height:0});
</script>
